Modeling Fraunhofer diffractive characteristics for modulation transfer function analysis of tilted ring metallic mesh
Modeling Fraunhofer diffractive characteristics for modulation transfer function analysis of tilted ring metallic mesh
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DOI：
10.1016/j.optcom.2011.04.040
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发表时间：
2011-08
影响因子：
2.4
通讯作者：
Zhengang Lu;Jiubin Tan;Jing Qi;Z. Fan;L. Zhang
中科院分区：
文献类型：
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作者：
Zhengang Lu;Jiubin Tan;Jing Qi;Z. Fan;L. Zhang
为了分析倾斜环形金属网格的夫琅和费衍射特性和调制传递函数（MTF），利用惠更斯-菲涅耳衍射理论建立了夫琅和费衍射光强分布模型，并直接在倾斜网格平面内进行衍射积分。计算结果与实验结果吻合较好，证明了所建立模型的正确性。基于所建立的数学模型和傅里叶变换，计算了金属网栅光学系统的调制传递函数。分析表明，无论是垂直于光轴还是倾斜于光轴，环形网格的衍射对MTF的影响都远小于正方形网格。因此，在光学窗口中使用环形网格作为高通滤波器时，可以提供比方形网格更高的成像质量。本文提出了一种斜阵列衍射调制因子，它不仅适用于斜正方形网格和斜环形网格的衍射特性分析，而且可以推广到其它斜衍射阵列的夫琅禾费衍射特性分析。
In order to analyze the Fraunhofer diffractive characteristics and modulation transfer function (MTF) of a tilted ring metallic mesh, an optical intensity distribution model of Fraunhofer diffraction is built using Huygens–Fresnel diffraction theory and the diffraction integral is carried out directly in the tilted mesh plane. The diffraction characteristics of the tilted ring metallic mesh are in good agreement with experimental results, which proves the correctness of the model established. MTF of an optical system with metallic mesh is calculated based on the model established and Fourier transform. Analysis shows that the degradation of MTF caused by diffraction of a ring mesh is much less than that of a square mesh whether they are vertical or tilted to the optical axis. Therefore, ring mesh can provide higher imaging quality than square mesh when they are used as high-pass filters in optical windows. A tilted array diffraction modulating factor is abstracted and believed useful in the analysis of diffractive characteristics of tilted square mesh and ring mesh, and it can be extended to Fraunhofer diffractive characteristics analysis of other tilted diffraction arrays.